Telegraph system.



, rares.

JOI-IN HUME BELL, OF EAST ORANGE, NEW JERSEY, ASSIGNOR TO WESTERN ELECTRIC COMPANY INCORPORATED, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

TELEGRAPH SYSTEM.

Specification of Letters Patent.

Patented italy et,

Applicationled July 12, 1917. SerialiNo. 150,199.

To all whom t may concer/n.'

Be it known that I, JOHN H. BELL, a citizen of the United States, residing at East Grange, in the county of Essex and State of New Jersey, have invented certain new and useful Improvements in Telegraph Systems, of which the following is a full, clear, concise, and exact description.

This invention relates to telegraph systems, and more particularly to telegraph transmitting apparatus and systems wherein current changes may be readily set up and imparted to a single line conductor all in a manner to permit such currents to be translated into telegraphic code characters, or to be reproduced in a printed form by suitable receiving apparatus at a distant station.

The object of this invention is to provide a telegraph transmitter capable of performing the necessary functions in a reliable and eiiicient manner to render service of special value in connection with 'line conductors having low time constant characteristics as in submarine cable working.

In carryin out this invention, electroresponsive swltching means are provided for selecting predetermined circuits adapted to affect the potentials of currents supplied from an: alternating current source, a distributing means bemg provided for establishing such prepared circuits effective to control the strength of signaling impulses impressed on a line conductor.

This invention is illustrated diagrammatically in the accompanying drawing in which only so much of a transmitter equipment is shown as will be necessary to a clear understanding of the present invention.

`Referring to the drawing, a main line 3 of a current transformer 2, to an earth' connection 5. A bipole alternating current generator 8 is connected to form a closed circuit through a winding 4 of the transformer 2, and reiistance units 9 and 10. A source of direct current supply 14 is provided to act in connection with transmitter initiating contacts 20, 30, 40, 50, and 70 for operating respective ones of impulsel modifying relays or switching units 22, 32, 42, 52, 62 and 72. A lock-release relay 80 is provided for denergizing, at a proper moment, any one of the impulse modifying relays which may have been energized in the setting up of a three-unit code signaling impulse combination. A current distributer 0r switching unit 90 carries a contacter arm 91, adapted to be rotated by means (not shown) in a counterclockwise direction for sweeping over the segments 94, 95 and 96 in picking up telegraphic impulses and over segment contacts 97 and 99 to control the lock-release relay 80. Conductors l?, 18 and 19, extending in derived circuit relation from the resistance units 9 and l0, are connected to coperate with the contact members of the impulse modifying relays and the contactor segments of the current distributer` 90 in setting up conditions for varying the potentials and strengths of alternating currents which are established through the transformer 2 by the generator 8. Such changes in currentstrengths in the transformer 2 follow predetermined signaling combinations, and as such eii'ect corre sponding current changes in the main line conductor 1.

In more specifically describing the operations by which the features of this invention may be practised, let it first be understood that the contacts 20, 30, 40, 50, 60 and are preferably to be arranged and equipped in a manner to permit operation thereof to be controlled by means of a punched or perforated tape, all a well known manner and as commonly employed with printing telegraphs. The moving parts of the generator 8, current distributor 90, and the forward travel of the perforated tape are to be correlated in such a manner that circuit completion from each one of the segments 94, 95 and 9G of the distributer 90 will be in unison with a one-half cycle or an ,alternation from the generator 8. and' conductor 1 connects, through one winding? fthe operation of the locl: release relay 80, to

denergize the impulse modifying relays 32, 42, 52, 62 and 72, may take place at the zero current pliase angle moment of the current cycles from the alternating current generator 8.

For convenience of description, let it now be assumed that the generator 8, distribut-cr 90. and a. perforated transmitting message tape (not shown), are all suitably active to set up and impart to the line conductor l, three-unit impulse cycles of telegraphic currents. And let` it be further assumed that an alternation of incremented maximum current of positive polarity, a minimum current strength negative alternation, and ancorresponding Awith the letter I which Will nov be considered. The perforated transmitting strip will first eifect the closing of f contacts and 60, thereby establishing tWo circuits one of which extends from the grounded current source 14, bus conductor 16, contacts 30, conductor 31, Winding of the relay 32, conductors 33 and 13, and the contacts 81ml' the lock-release relay 80 to an earth connection 82. Through this circuit the relay is initially operated to establish a self-locking path through its contacts 34 and conductor 15 to the source 14. This relay thereby' prepares an impulse circuit which may `be traced from the bus conductor 19 of the generator 8, conductor 35, contacts 36 of the relay 32 and conductor 37 to the segment 94 of the distributor 90.

At the instant the contactor arm 91 arrives at the segment 94, the driving arrangement (not shown) will have movedy the armature of the alternating/ current generator 8 tov the zero current phase point following which a positive alternation half-Wave of current will be generated and imparted to the bus conductorlQ, thence to traverse the circuit, just traced, to the segment 94 of the distributer 99, During the time the contactor arm 91 is passing over the segment 94, it completes a connection by its spanner type brush 92 from this segment to the common contact ring 93 from which the conductor 17 extends to the derived circuit connection at a point between the resistance unit 10 and the Winding 4 of the transformer 2. Therefore, it `Will be apparent that, during the activity of. the positive alternation of current from the generator 8, the circuit, just traced through the contacts of the relay'32 and the distributor 90, will edect a shunt path therefor around each. one of the resistance units 9 and 10, thereby reducing the resistance of the closed generator circuit, permitting the generator to therein develop an incremented current of high or'maximum current value. This current acting in the primary winding 4 of the transformer 2 sets up a correspondingly characteristic current in the secondary winding 3 of the transformer. Such induced current in the Windin r 3 of the transformer completes circuit roml the earth connection 5 and the main line conductor 1 to an earth connection at a distant receiving station (not shown). For the second current impulse unit of the code for the letter I, no action takes place with respect to the perforated strip controlled contacts or at the distributer 90. During the time the contactor arm 91 of the distributer is passing over the present non-energizing segment 95 (the circuit of this segment noW standing open at the contacts 46 and 56 of Agenerator circuit already traced, thereby reducing to a predetermined minnnum the `strength of this impulse of current through the/primary Winding 4 of the transformer 2. Accordingly, a correspondingly reduced current Wave will be set up in the line circuit 1' by Way of the secondary Winding 3 of the transformer. In setting up and imparting the third or last impulse unit to the line circuit 1, the perforated transmitting tape having already closed the contacts as mentioned, thereby completes a circuit from the current source 14, bus conductor 16, contacts 60, conductor 6l, winding of the relay 62, conductors 63 and 13, and contacts 81 of the 100k-release relay 80 to the earth connection 82. Energization of the relay 62 thereby takes place, and, through its contacts 64'and the bus conductor 15, a selflocking path is established from the current source 14. An impulse circuit prepared by the operation of this relay extends from the generator bus 19, resistance unit 9, bus conductor 18, conductor 65, Contact 66 of the relay 62, thence over conductor 67 to the segment 96 of the distributer 90. At the instant the contacter arm 91 arrives at the segment 96 of the distributer 90, the armature of the generator 8 will be just leaving the zero current point of its phase angle to set up an alternation of current having positive polarity With respect'to the generator bus conductor 19.. During the time the contactor arm 91 is traversing the segment 96, the negative alternation present thereon Hows over this arm. to the common ring 93, thence over the conductor 17 to the derived circuit point on the closed generator loop already described. From the circuit traced, it Will be noted that the contacts 660i the relay 62 and the distrihuter 90 establish a shunt path around the resistance unit 10. The resistance unit 9, now vbeing alone in series. with the generator 8 and primary Winding 4 of the transformer 2, it follows that the current action in this circuit will be incremented to a medium or mean strength with respect to the first two impulse units described. Therefore, through the action of the transformer 2, the secondary Winding 3 thereof will impart a current wave of corresponding strength to the line conductor 1. immediately after passing from the segment 96, the contactor arm 91 of the distributor 90 establishes a connection betvveen the contacts 97 and 99, thereby completmga circuit which may be traced from thereby disconnecting the self-locked relays A32 and 62, which immediately resume their inert or normal condition. As already mentioned, this operation of the lock-release relayl 80 and the resulting denergizing of any one of the relays 22, 32, 42, 52, 62 and 72, which may have been employed in setting up a transmitted three-unit code of impulses, may take place at a time when the armature of the alternating current generator S is at a zero current point of its cycle.

From the foregoing description, it Will be apparent that the contacts 24, 34, 44, 54, 64 and 74 serve to establish individual locking circuits for respective ones oi the relays 22, 32, 42, 52, 62 and 72, the locking circuit being eii'ective after a relay has initially responded to a momentary closing of its respective one of the contacts 20, 30, 40, 50, and 70. It will also be noted that contacts 26, 46, and 66 of the corresponding relays 22, 42 and 62 establish direct connection from the derived circuit bus conductor 18 to respective ones of the segments 94, 95 .and 96 of the distributer 90,' thereby shunting out the resistance unit 10 during the time the contactor arm .91 may be active on these segments. And further, that contacts 36, 56 and 76 of corresponding relays 32, 52 and 72 establish a shunt path from the generator bus conductor 19 to respective ones of the segments 94, 95 and 96, thereby short-circuiting both of the 'resistance units 9 and l0 during the time the contactor arm 91 may be present over either one of these segments.

Directing attention to the three idle segments on t e lowermost half of the distributer 90, it will be understood that a second group of relays and controlling contacts therefor, similar to those shown in the drawing, may be interconnected in like manner to these segments, thereby permitting such second transmitter to Work to the line conductor 1 in multiplex relation with the transmitter shown. For multiplex Working, it will be apparent that, during the time the contacter arm 91 of the distributer 90 is traversing the three lowermost segments,

the perforated transmitting tape may continue active in selecting ones of the relays 22, 32, 42, 52, 62 and 72 for preparing circuit conditions for a next cycle of threeunit code impulses at the segments 94, 95 and 96 and vice versa with respect to action in theequipment for the second transmitter during the time the arm 91 is over the three uppermostsegments. In providing equipment for a second transmitter group, it will be understood that an individual lock-release relay would be required therefor and that this relay may be under control of contacts (not shown) but similar to, and located directly opposite, theY contacts 97 and 99, which control the present lock-release relay 89.

What is claimed is: p

1. In a telegraph system of the class wherein means under the control of relays are employed for varying the strength of half-Waves from a source of alternating current to effect signaling, the combination of contacts for selectively preparing in advance of service operative combinations of said relays, and distributer means for establishing operated ones of said relays effective with said means for varying-the strength of halfwaves of currents from said alternating current source. f

2. In a telegraph system, a source of alternating currents, a plurality of relays, a distributer, resistances jointly controlled by said relays and said distributer for affecting the strength ofv successive alternations from said source of current, and a relay for disablin said first mentioned relays.

3. n a telegraph system, a plurality of relays, a, source of alternating currents, a distributer, resistancee, transmitter switching means for selemively operating said relays in preparing cirmts whereby said resistances may be made e'ective to control the strength of currents from said current source, a relay for retaining said first mentioned, relays operated, and distributer means to cooperate with the relays in establishing said resistances effective to vary the strengtho'f successive impulses ofV current from said source.

In witness whereof, 1 hereunto subscribe my name this 10th day of July A. vD., 1917.

'Y Jona HUME BELL. 

